Sidewall for a cup



FIG. 1 is a top perspective view of a sidewall for a cup showing our new design;

FIG. 2 is a side view of the sidewall for a cup of FIG. 1;

FIG. 3 is a top view of the sidewall for a cup of FIG. 1; and,

FIG. 4 is a bottom view of the sidewall for a cup of FIG. 1.

The broken lines shown throughout these figures depict environmental subject matter only and form no part of the claimed design. 

The ornamental design for a sidewall for a cup, as shown and described. 